Invaders from another world have crossed into the world of Yorros and Kyrryl and kidnapped a felinoid Tariling child of only a year old to use in a ceremony to summon a great evil into their world. The sacrifice needs to be something innocent, and the child Tayio more than fits the bill. Yorros and Kyrryl, while human, are friends with the parents of Tayio, and with their niece, Ashara, go on a quest to find Tayio and his kidnappers and bring back the child.
Meanwhile, in another world, Ellish, Sirado, Dayshan, Hallin, Roshan, and Trasho are humans riding their lands on a holiday outing and looking for Kian Dae, who is missing, when they become aware that they have passed through a portal into another world. Joining them is Kian Dae, a large hunting cat that is actually the conduit through which Pasht, a goddess, helps them by allowing them to speak the local language and keeps watch over their party.
On the third world they both end up on, there are the traders Anatiah and Kaitlin, who are goddess-bonded to each other through Pasht. While Anatiah is human, Kaitlin is a felinoid race called an Aradian. The two are in love and their marriage/bonding is considered slightly shocking. They encounter two crooked traders, Vani and Shaetyl, who have in their train Aycharna, a human enslaved through shady doings with the help of a corrupt magistrate. She can pick locks and is desperately trying to escape, but she knows that if she returns to her former home city, she will merely be enslaved again... unless she can find her way to somewhere else and escape her captors and their hunters.
She is found by Anatiah and Kaitlin, who have heard such stories before and are no longer shocked to hear such things. But they sympathize with her and take her in as she recovers from her ordeal. Maybe they can add her to their travelling band? If they can trust her, that is.
Though none of the parties yet know it, a horrible war is coming that will shake the foundations of the world, and only they can somehow prevent it, a war involving demons from another dimension flooding the world to destroy it- and the sacrifice of Tayio is to be the culmination to completely destroying the wall preventing the demons from entering the world wholesale. When the combined parties meet up and discover that Vani, Shaetyl, and their entire caravan have been slaughtered by demons, they know that they must report this development to the authorities. But that means going back to the city where Aycharna was imprisoned, and somehow keeping her safe and preventing her from being enslaved and imprisoned once more. Can they prove that her enslavement was unjust and illegal?
And as they work with the military of this world to beat back the demons who are already here, can they save Tayio from the fate he is meant for by his kidnappers, and prevent the wholesale invasion of yet more demons? Meeanwhile, one of their own has been seduced to the side of the demon cultists and stands ready to destroy the group they are with. But can they take out the traitor before their entire quest is sunk?
The most interesting thing about this book, aside from the gripping story, is that this is an entirely stand-alone novel. None of the characters from the three different worlds have ever been written about before, or have ever been introduced elsewhere, but that isn't how the story reads. All three worlds in the story, and all the characters from those worlds are so well-developed that it seems as if this is the culmination of an entire series. The characters feel easy with each other, and the worlds as if they have existed and been explored many times before.
Before long, you are swept into the story, and hang on the edge of your seat, wanting to know what happens next. So many plot threads pile on each other that you might think they would devolve into a confusing mess, but the plot threads interweave so well that they become a seamless whole, even the greedy traitor plot. And Tayio is never forgotten, showing up from time to time so that readers can see what is happening with the original cultists who kidnapped him.
This book may be a stand-alone novel, but I wish it wasn't. I'd love to see the various characters in adventures in their own worlds. Each is so well-developed, that I want to see more of them and spend more time examining their home worlds. I'd recommend this book to anyone who loves fantasy, and especially those people who loved the style of fantasy that Andre Norton wrote, because it has that sort of vibe to it. Highly recommended.